1. Field of the Invention
The present invention relates to a built-in antenna of a portable terminal. More particularly, the present invention relates to a multiband built-in antenna of a portable terminal for simplifying a manufacturing process, reducing an assembly cost, and achieving a slimmer design.
2. Description of the Related Art
Today, terminals have various functions and designs. Although the terminals are becoming lighter, thinner, and simpler, the functions of the terminals are still important to meet user's demands. Thus, it desirable to reduce the volume of the terminals while maintaining or improving the functions of the terminals.
Among the aforementioned terminals, a folder type terminal and a slide type terminal are particularly dominant in the market. This is because, when the terminal is not used or is carried, the length of the terminal in the carrying position is reduced by half relative to an operating state by folding or sliding a sub body back within a main housing.
However, a bar type terminal equipped with a Liquid Crystal Display (LCD) module in a front surface thereof has been widely used in recent years. This is because the terminal operates by using a touch screen while avoiding a keypad utilizing a metal dome as user's preference varies. In this type of terminal, an outwardly protruding antenna has been conventionally deployed. For example, a rod antenna (or a whip antenna) and a helical antenna which protrude outwardly by a specific length from the terminal have been used, but these antennas are most susceptible to drop damage and reduce portability of the terminal. Therefore, a built-in antenna (i.e., so called an ‘internal antenna’ or an ‘intenna’) installed inside the terminal is now widely used. Various efforts have been made to improve a characteristic of the built-in antenna to improve assembly capability and productivity.
The aforementioned plate type antenna is installed on a carrier having a specific height and provides a distance between a ground surface and a main board located in a lower portion thereof, thereby implementing smooth radiation performance. Further, the antenna is typically configured to implement multiple bands (e.g., at least two resonance points) by using one radiator. This is because a slot pattern on a front surface of the radiator can be formed in various manners according to each desired band. For example, since Wideband Code Division Multiple Access (WCDMA), a Digital Cellular System (DCS), and a Global System for Mobile Communication (GSM) can be used together by one terminal, the terminal having such design can be used more conveniently.
Meanwhile, in recently introduced slide type terminals, bar type terminals, folder type terminals, etc., the aforementioned multiband antenna is located near a lower portion of a main body, i.e., near a position where a speaker is installed. More particularly, the antenna radiator is installed in a direction of a front surface of the terminal. This is one way of utilizing a limited space of the terminal efficiently which is continuously becoming slimmer.
However, as described above, the implemented antenna requires an additional carrier and is equipped with the antenna radiator in which a specific pattern is formed in an upper portion of the carrier. Therefore, there is a problem in that the antenna occupies a useful inner space of the terminal and an installation position is limited. Further, the number of constitutional parts of the terminal increases which in turn increases the assembly cost. Increasing components inside the terminal is not desirable when the trend is for a slimmer terminal.